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Biomedical subjects

L Agati

Publications and source records attributed to L Agati.

At least 19 recordsLinked to original sources
PubMed2005

Impact of intracoronary aspiration thrombectomy during primary angioplasty on left ventricular remodelling in patients with anterior ST elevation myocardial infarction.

OBJECTIVE: To evaluate prospectively the impact on left ventricular (LV) remodelling of an intracoronary aspiration thrombectomy device as adjunctive therapy in primary percutaneous coronary intervention (PCI) in patients with anterior ST elevation myocardial infarction (STEMI). METHODS: 76 consecutive patients with anterior STEMI (65.3 (11.2) years, 48 men) were randomly assigned to intracoronary thrombectomy and stent placement (n = 38) or to conventional stenting (n = 38) of the infarct related artery. Each patient underwent transthoracic echocardiography immediately after PCI and at six months. At the time of echocardiographic control, major adverse cardiovascular events (MACE) in terms of death, new onset of myocardial infarction, and hospitalisation for heart failure were also evaluated. RESULTS: After a successful primary PCI, patients in the thrombectomy group achieved a higher rate of post-procedure myocardial blush grade 3 (36.8% v 13.1%, p = 0.03) and effective ST segment resolution at 90 minutes (81.6% v 55.3%, p = 0.02). Six months after the index intervention, 19 patients (26.8%) developed LV dilatation, defined as an increase in end diastolic volume (EDV) >or= 20%: 15 in the conventional group and four in the thrombectomy group (p = 0.006). Accordingly, at six months patients treated conventionally had significantly higher end systolic volumes (82 (7.7) ml v 75.3 (4.9) ml, p < 0.0001) and EDV (152.5 (18.1) ml v 138.1 (10.7) ml, p < 0.0001) than patients treated with thrombectomy. No differences in cumulative MACE were observed (10.5% in the conventional group v 8.6% in the thrombectomy group, not significant). CONCLUSION: Compared with conventional stenting, adjunctive aspiration thrombectomy in successful primary PCI seems to be associated with a significantly lower incidence of LV remodelling at six months in patients with anterior STEMI.

Adult↗
PubMed2005

Quantification methods in contrast echocardiography.

New technologies and the availability of new echo-contrast agents have resulted in advances of diagnostic and prognostic indications of left ventricular opacification (LVO) and myocardial perfusion. The clinical diagnostic value of ultrasound contrast media for LVO and its impact on the clinical decision-making process has been demonstrated in several studies. Recent research aims at developing new quantitative software to improve the delineation of the endocardial border, to assess 3D myocardial perfusion for more accurate regional/global LV function measurements, and to evaluate 4D intra-cardiac flow dynamics. Furthermore, a general consensus has been reached on the incremental value of myocardial contrast echocardiography (MCE) for obtaining additional information in both chronic and acute coronary artery disease (CAD) patients and on the possibility to make quantitative measurements of microvascular damage. Q-contrast is a new software system which provides quantitative measurements to generate parametric images of microcirculatory flow. In a research project including 120 patients, Q-contrast software has been tested to assess the role of contrast in AMI (Acute Myocardial Infarction Contrast Imaging (A.M.I.C.I. Study); good agreement between parametric MCE and SPECT has been found. Preliminary results further confirm that quantitative MCE may provide additional clinical value over qualitative information for the assessment of LV function and of the effects of coronary artery disease on the myocardial microcirculation (viability, ischemia or infarct).

Aged↗
PubMed2003

[Myocardial contrast echography. History, methodology and clinical applications].

Recent studies have demonstrated the usefulness of myocardial contrast echocardiography (MCE) in studying myocardial perfusion. Several first and second generation contrast agent such as Levovist, Sonovue, Optison, Definity and Imagent are commercially available or close to be introduced into the market. Use of MCE allowed the clinical demonstration of no-reflow phenomenon in patients with acute myocardial infarction (AMI) after recanalization of the infarct related artery (IRA). Coronary angiography is unable to assess the microvascular damage as showed by the poor correlation between TIMI grading and perfusion score evaluated by MCE. Furthermore, the use of MCE is important to determine coronary stenosis, to identify microvascular damage during ischaemia-reperfusion and to evaluate the presence of collateral circulation in the area at risk. MCE seems to be the most effective technique for assessing microvascular integrity after reperfusion as compared to TIMI myocardial perfusion grade, nuclear myocardial perfusion imaging and magnetic resonance imaging. These techniques are expensive, invasive and not available in most of the hospitals. Furthermore, as compared to nuclear medicine and echo-dobutamine, MCE has greater specificity and higher accuracy in detecting coronary artery disease. Recent studies showed that not only primary percutaneous coronary intervention (PCI) but also rescue and delayed PCI reduced microvascular damage and that MCE play a key role in assessing myocardial salvage after reperfusion. The most exciting aspect of MCE is the independent role in predicting left ventricular (LV) remodelling and functional recovery. The extent on no-reflow is an important predictor of LV dysfunction and remodelling at follow-up. Several studies have demonstrated that the extent of infarct-zone viability is a powerful independent predictor of LV dilation. There is a close relationship between the extent of microvascular damage, the extension of necrosis, the site of AMI and LV remodelling. We demonstrated that MCE performed 24 hours after reperfusion, at 1 week and 6 months appears to provide important prognostic information. These data support the daily use of MCE in coronary care unit and could establish a strategy for clinical decision making in patients with AMI.

Contrast Media↗
PubMed2001

Assessment of no-reflow phenomenon after acute myocardial infarction with harmonic angiography and intravenous pump infusion with Levovist: comparison with intracoronary contrast injection.

Myocardial contrast echocardiography (intracoronary application) has emerged as an accurate method to detect the "no-reflow phenomenon." To investigate the diagnostic value of harmonic angiography after intravenous infusion of Levovist in assessing "no-reflow," both intracoronary and intravenous contrast injections were performed in a group of patients with acute myocardial infarction. Seventeen consecutive patients with a successfully reperfused acute myocardial infarction within 6 hours of symptom onset were selected for this study. All patients underwent contrast echocardiography with harmonic angiography with Levovist (400 mg/mL, intravenous pump infusion, trigger intervals 1:4 to 1:8) and sonicated albumin (0.5 to 1 mL, intracoronary bolus) on day 1 after the achievement of a sustained coronary reflow. Myocardial perfusion was qualitatively assessed with a 12-segment model. The endocardial length of the residual contrast defect after reflow was also calculated. Forty-four of 204 segments were not analyzed after intravenous contrast echocardiography and 37 after intracoronary contrast echocardiography because of artifacts. Intracoronary and intravenous injections showed a perfusion defect in 31 (19%) segments, with a concordance of 89% (kappa coefficient, 0.72). Concordance in anteroseptal, anterolateral, and inferolateral segments was 95% (kappa = 0.92), 88% (kappa = 0.66), and 83% (kappa = 0.57), respectively. With intracoronary injection used as the reference method, intravenous injection had a sensitivity of 74% and a specificity of 93% for diagnosing contrast defects. The endocardial extent of no-reflow was 18 +/- 19 after intravenous and 21 +/- 17 after intracoronary contrast echocardiography (P = not significant). Intravenous contrast echocardiography with Levovist reliably identifies the no-reflow phenomenon after successful reperfusion, especially in acute anteroseptal myocardial infarction.

Contrast Media↗
PubMed2001

Non-invasive assessment of myocardial perfusion by intravenous contrast echocardiography: state of the art.

Many technical problems, related to both imaging instrumentation and contrast agents, have to be taken into account before attempting non-invasive evaluation of myocardial perfusion by intravenous contrast media injection. Potentials and pitfalls of first generation contrast agents (i.e. Levovist, Schering AG, Berlin, Germany) using intermittent harmonic angio imaging and of second generation contrast media (i.e. SonoVue, Bracco SpA, Milan, Italy) using real-time perfusion imaging in the non-invasive assessment of myocardial perfusion were described and discussed. We still need more solid data before introducing intravenous myocardial echocardiography into the clinical arena. However, convincing data from several research laboratories are paving the way for the widespread use of this new method in clinical practice.

Cardiomyopathies↗
PubMed2000

Role of echocardiography in acute chest pain syndrome.

Fewer than one third of patients presenting to the emergency department with complaints of chest pain have an acute coronary syndrome. The electrocardiogram provides a specific diagnosis only in 40% of patients with acute myocardial infarction. The presence of regional wall-motion abnormalities at echocardiography in patients without known coronary artery disease is a moderate indicator of an increased likelihood of acute myocardial ischemia or myocardial infarction with a positive predictive accuracy of about 50%. More important, the absence of regional wall-motion abnormalities identifies a subset of patients unlikely to have a myocardial infarction with a negative predictive accuracy of about 95%. Echocardiography can provide incremental prognostic information to identify patients at risk of early or late cardiac events, even after consideration of clinical, historical, and electrocardiographic variables. The application of new contrast agents to echocardiography will probably allow an early and more accurate evaluation of patients with chest pain of uncertain significance.

Acute Disease↗
PubMed2000

Detection of residual tissue viability within the infarct zone in patients with acute myocardial infarction: ultrasonic integrated backscatter analysis versus dobutamine stress echocardiography.

OBJECTIVES: The goals of this study were to analyze temporal changes in cardiac cyclic variation of integrated backscatter (CVIB) in acute myocardial infarction (AMI) and to investigate the predictive value of CVIB normalization compared with that of dobutamine stress echocardiography (DSE) in the assessment of functional recovery after revascularization. BACKGROUND: The normal CVIB is blunted by ischemia and recovers early after reperfusion, faster than wall motion improvement. Analysis of CVIB has been widely investigated for its potential to detect viable myocardium in the early stage of infarction. No studies have compared CVIB analysis with other techniques for viability assessment in patients with acute ischemic. METHODS AND RESULTS: Integrated backscatter images were obtained in 12 patients with AMI on days 1, 3, and 7 after admission and 1 month after revascularization. On day 7, DSE was performed in all patients. On admission, 22 of 144 segments were dyssynergic. On day 1, CVIB was abnormal in all 22 infarcted segments, on day 3, in 16, and on day 7, in only 10 infarcted segments. Eight of 10 segments nonviable by CVIB (CVIB-nonviable) were also nonrespondent by DSE; whereas 12 of 14 segments viable by DSE (DSE-viable) were also CVIB-viable. At follow-up, 10 CVIB-viable segments and 1 CVIB-nonviable segment showed functional recovery; whereas 10 of 14 DSE-viable segments showed functional recovery. Thus the positive predictive value of CVIB and DSE was 83% and 72%, respectively, with a diagnostic agreement between techniques in 77% of segments. CONCLUSIONS: Our data suggest that the normalization in CVIB in the first week after AMI accurately predicts residual tissue viability within the infarct zone. We also observed that the initial pattern of cyclic variation may be predictive of functional recovery. Finally, we found a good correlation between the recovery of a normal CVIB in segments that were still dysfunctional and a more validated method to assess tissue viability, such as the dobutamine test.

Adult↗
PubMed2000

Harmonic imaging with Levovist for transthoracic echocardiographic reconstruction of left ventricle in patients with post-ischemic left ventricular dysfunction and suboptimal acoustic windows.

BACKGROUND: Attempts to perform transthoracic 3-dimensional echocardiography (3DE) are often encumbered by poor definition of chamber borders in adult patients who have technically suboptimal acoustic windows. METHODS: To assess whether harmonic imaging (HI) and contrast agents can facilitate transthoracic 3DE assessment of the left ventricle, we used fundamental imaging (FI), HI alone, and HI coupled with the echo-enhancing contrast agent Levovist in 15 consecutive patients with post-ischemic left ventricular (LV) dysfunction and technically difficult windows. Dynamic 3DE image data sets were obtained at 5-degree angles (36 slices) from a transthoracic apical view. From these data a total of 240 myocardial segments were analyzed with the use of dynamic short-axis paraplane slices at basal, middle, and apical LV levels (standard 16 segment model). For border definition, each segment was scored in random sequence on the following scale by 2 independent investigators: 0 = not seen, 1 = suboptimal visualization, and 2 = well defined. RESULTS: Our results showed a significant increase in the number of well-visualized segments when harmonic mode combined with Levovist injection was compared with FI and HI alone. CONCLUSION: Harmonic imaging alone improves LV assessment by 3DE when compared with FI. Contrast imaging in which Levovist is added to HI further improves the capability of transthoracic tomographic 3DE in the visualization of LV myocardial segments. This could allow 3DE by transthoracic windows to be used more widely in adults for the evaluation of LV volume and function.

Adult↗
PubMed2000

Enhanced left ventricular endocardial border delineation with an intravenous injection of SonoVue, a new echocardiographic contrast agent: A European multicenter study.

The safety and efficacy of SonoVue (also referred to as BR1), a new contrast agent for delineating endocardial border of the left ventricle after intravenous administration, was assessed. Two hundred and eighteen patients with suspected coronary artery disease undergoing fundamental echocardiography for the assessment of left ventricle were enrolled in a prospective multicenter, single blind, cross-over study with random sequence allocation of four different doses of SonoVue. Endocardial border definition in the apical and parasternal views was scored as 0 = not visible, 1 = barely visible, and 2 = well visualized before and after contrast enhancement. Analysis was performed by two pairs of off-site observers. Safety of SonoVue was also assessed. Results of our study indicated that the mean improvements in the endocardial border visualization score were as follows: 3.1 +/- 7.8 (95% CI, 2.5 and 3.7) for 0.5 ml, 3.4 +/- 8.0 (95% CI, 2.8 and 4.0) for 1 ml, 3.4 +/- 7.9 (95% CI, 2.8 and 4.0) for 2 ml, and 3.7 +/- 8.0 (95% CI, 3.1 and 4.3) for 4 ml (P < 0.05 for all doses from baseline). Changes from baseline in endocardial visualization scores were also seen in the apical views (P < 0.05) and they were dose-dependent (P < 0.001). Similar enhancements of endocardial visualization scores were observed in the apical views in patients with suboptimal baseline echocardiographic images. Diagnostic confidence for assigning a score and image quality also were significantly better following contrast enhancement. No significant changes in the laboratory parameters and vital signs were noted following contrast enhancement, and the side effects were minimal. It was concluded that SonoVue is safe and effective in delineating endocardial border, including in patients with suboptimal baseline images.

Aged↗
PubMed1999

Microvascular integrity after reperfusion therapy.

Several perfusion techniques have definitively shown that microvascular dysfunction plays a crucial role in patients with acute myocardial infarction. In those patients, despite a rapid and sustained restoration of flow throughout a previously occluded epicardial coronary artery, microvascular damage still may be observed. Duration of ischemia and/or time to recanalization are the most powerful determinants of microvascular dysfunction. However, the amount of tissue perfusion in infarcted patients is dependent on many other complex interrelated factors including extent of collateral circulation before recanalization, residual stenosis severity of the culprit artery, vasodilator reserve in the infarct territory, extent of reperfusion injury, and loading conditions. Because microvascular dysfunction is associated with progressive left ventricular dilation and a high frequency of postinfarction complications, all of the efforts to improve the relation between coronary reflow and microvascular perfusion are justified.

Collateral Circulation↗
PubMed1998

The complex relation between myocardial viability and functional recovery in chronic left ventricular dysfunction.

Preserved myocardial viability and recurrent symptomatic ischemia are the most widely accepted criteria indicating that coronary revascularization should take place in patients with postischemic left ventricular dysfunction. However, the presence of viable myocardium within the infarct zone does not necessarily imply recovery of function after coronary revascularization. The complex relation between the extent of transmural necrosis and the degree of residual perfusion within the infarct area plays an important role. However, independently of functional recovery, cell viability may have important clinical implications, since it may improve long-term prognosis by attenuating left ventricular remodeling processes. Several different methods are used to detect hibernating myocardium. Mounting evidence suggests that thallium-201 scintigraphy is most sensitive in identifying tissue viability, whereas dobutamine echocardiography is most specific in predicting functional recovery after revascularization. In between, myocardial contrast echocardiography is the only technique able to evaluate the microvascular integrity that is a condition sine qua non for both cell viability and later functional recovery. Combined information derived from these 3 different approaches might be considered as the best way to understand how the combination of contractile, viable but noncontractile, and dead tissue affect resultant function and prognosis.

Cardiotonic Agents↗
PubMed1998

Role of the central endogenous opiate system in patients with syndrome X.

BACKGROUND: To evaluate the role of the endogenous opioid system (EOS) in abnormal pain perception in patients with syndrome X, we used a neuroendocrine approach, evaluating plasmatic luteinizing hormone (LH) changes after naloxone, a competitive antagonist of opioid receptors able to unblock tonic EOS inhibition on gonadotropin release. Thus LH response to naloxone test indicates the central EOS activity on hypothalamic luteinizing hormone-releasing hormone (LH-RH) inhibitory opioid receptors. METHODS: Ten patients with syndrome X, 10 age-matched male patients with coronary artery disease (CAD), and 10 normal subjects were analyzed. Naloxone tests were performed between 8 and 9 am. Basal beta-endorphin and LH levels were determined on 4 blood samples at 20-minute intervals; after naloxone (0.1 mg/kg intravenously in 4 minutes), LH was measured on 8 samples at 15-minute intervals. In all patients the test was also performed after LH-RH administration. Anginal pain on exercise testing was subjectively scored on a 1 to 10 analogic scale and wall motion abnormalities were quantified by a wall motion score index. RESULTS: Significant differences were found in LH release after naloxone (CAD 260.3 +/- 42.6 vs syndrome X 151.6 +/- 48.5 mIU/mL, P <.05), angina score (CAD 5.5 +/- 1.3 vs syndrome X 7.2 +/- 1.7, P <.05), and wall motion abnormalities (CAD 3.6 +/- 1. 2 vs syndrome X 2.8 +/- 1.9, P <.05). CONCLUSIONS: The reduced LH release after naloxone in syndrome X, with a normal LH-RH response, suggests a lower central EOS activity, which may be related to the higher anginal pain perception.

Humans↗
PubMed1998

Tissue-type plasminogen activator therapy versus primary coronary angioplasty: impact on myocardial tissue perfusion and regional function 1 month after uncomplicated myocardial infarction.

OBJECTIVES: This study sought to compare the impact of primary coronary angioplasty and thrombolytic therapy for acute myocardial infarction (AMI) on 1-month infarct size and microvascular perfusion. BACKGROUND: The effect of the reperfusion strategies of primary coronary angioplasty and thrombolytic therapy on microvascular integrity still remains to be determined. METHODS: Sixty-two consecutive patients with a first AMI, undergoing intravenous tissue-type plasminogen activator (t-PA) therapy (32 patients, Group I) or primary angioplasty (30 patients, Group II), were studied. Only patients with 1-month Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 were selected for the study. Patients in whom primary angioplasty was unsuccessful or those with clinical evidence of failed reperfusion were excluded. Microvascular perfusion was assessed at 1 month by intracoronary injection of sonicated microbubbles. Contrast score index (CSI) and wall motion score index (WMSI) were derived using qualitative methods. RESULTS: At baseline there were no significant differences between groups for age, risk factors, time to hospital presentation, Killip class on admission, prevalence of multivessel disease or anterior infarct site, infarct area extension before reperfusion, peak creatine kinase levels and postinfarction treatment. Conversely, significant differences between groups were found at follow-up for percent residual infarct related-artery (IRA) stenosis (70 +/- 12 vs 36 +/- 14 [mean +/- SD], p = 0.0001), CSI (1.02 +/- 0.4 vs. 1.49 +/- 0.5, p = 0.0003) and WMSI (1.67 +/- 0.3 vs. 1.45 +/- 0.3, p = 0.015). In particular, in the subset of patients with TIMI grade 3 flow, a perfusion defect occurred in one or more segments subtended by the IRA in 72% of Group I versus 31% of Group II patients (p < 0.00001) and in 27% of Group I versus 8% of Group II segments (p < 0.00001). CONCLUSIONS: The present study shows, in a highly selected cohort with successful IRA recanalization, that primary angioplasty is more effective than thrombolysis in preserving microvascular flow and preventing extension of myocardial damage at 1-month after AMI.

Age Factors↗
PubMed1997

Clinical and prognostic usefulness of supine bicycle exercise echocardiography in the functional evaluation of patients undergoing elective percutaneous transluminal coronary angioplasty.

BACKGROUND: Supine bicycle exercise echocardiography (SBEE) has never been used before and early after percutaneous transluminal coronary angioplasty (PTCA) for assessing the functional outcome of the procedure and predicting late restenosis. METHODS AND RESULTS: We selected 76 subjects with stable angina, normal wall motion at rest, and exercise-induced wall-motion abnormalities before PTCA. SBEE with peak exercise imaging and the use of a 16-segment, four-grade score model was performed 54 +/- 15 hours after PTCA. No exercise-related adverse events occurred. Patients were grouped according to SBEE results: group 1 (n = 35, 46%) with negative exercise ECG and echo; group 2 (n = 19, 25%) with a positive exercise ECG but normal echo; and group 3 (n = 22, 29%) with a positive exercise echo with either a positive (n = 7, 32%) or negative (n = 15, 68%) ECG. Exercise performance significantly improved in all groups. In group 3, peak wall-motion score index decreased from 1.27 +/- 0.11 before to 1.15 +/- 0.06 after PTCA (P < .05), and duration of wall-motion abnormalities went from 81 +/- 24 to 47 +/- 19 seconds (P < .05). The rate of clinical restenosis (ie, angina recurrence or positive 6-month SBEE in asymptomatic patients, both associated with angiographic restenosis > 50%) was 37%. By multiple logistic regression analysis, clinical restenosis was associated with a positive post-PTCA exercise echo (odds ratio [OR] 3.08, 95% confidence interval [CI] 1.66 to 5.72; P = .0004) and with increasing values of pre-PTCA wall-motion score index (OR 2.86, 95% CI 1.92 to 4.27; P = .005) and duration of wall-motion abnormalities (OR 2.12, 95% CI 1.07 to 4.20; P = .04). CONCLUSIONS: SBEE is a safe and reliable tool to demonstrate changes in exercise-induced wall-motion abnormalities after PTCA and provides prognostic information in the risk assessment of clinical restenosis.

Adult↗
PubMed1997

Combined use of dobutamine echocardiography and myocardial contrast echocardiography in predicting regional dysfunction recovery after coronary revascularization in patients with recent myocardial infarction.

BACKGROUND: Myocardial contrast echocardiography and dobutamine echocardiography have recently emerged as potentially useful clinical tools to detect reversible myocardial dysfunction. However, the relative accuracy of these two techniques in predicting regional wall motion improvement after coronary interventions is still unclear. The aim of the present study was to compare their diagnostic value in predicting functional recovery after coronary revascularization in patients with recent acute myocardial infarction. METHODS AND RESULTS: Twenty-four patients with acute myocardial infarction underwent myocardial contrast echocardiography and dobutamine echocardiography within 2 weeks of hospital admission. Infarct zone contrast score and wall motion score indexes were derived in each patient. Infarct-related artery revascularization was performed before hospital discharge in all selected patients. Resting echocardiography was repeated 3 months after revascularization, and regional function recovery was analysed. The degree of wall motion score improvement at 3-month follow-up and the percentage of positive responses to dobutamine echo were greater (P < 0.001 and P < 0.002, respectively) in patients with a higher baseline contrast score (> or = 0.50). Conversely, no significant changes were observed either during dobutamine echo or after revascularization in the group of patients without residual perfusion within the infarct area. Diagnostic agreement between both techniques in predicting reversible dysfunction was high (81% of segments). The sensitivity and negative predictive value in predicting functional outcome were 100% (95% confidence interval [CI], 87% to 100%) and 100% (95% CI, 93% to 100%) by contrast echo, and 85% (95% CI, 66% to 96%) and 93% (95% CI, 84% to 98%) by dobutamine echo. The specificity and positive predictive value were 90% (95% CI, 80% to 96%) and 81% (95% CI, 64% to 93%) by contrast echo, and 88% (95% CI, 78% to 95%) and 76% (95% CI, 58% to 90%) by dobutamine echo. The combination of myocardial contrast and dobutamine echocardiography positive responses improved specificity and positive predictive value in detecting functional recovery after revascularization to 100% (95% CI, 94% to 100%) and 100% (95% CI, 85% to 100%), respectively. However, the sensitivity and negative predictive value slightly decreased with the use of both methods (85% [95% CI, 66% to 96%)] and (93%[95% CI, 85% to 98%)], respectively. CONCLUSIONS: In patients with recent myocardial infarction, reversible dysfunction after coronary revascularization and the response to dobutamine infusion are strictly dependent on microvascular integrity. However, microvascular perfusion does not always imply functional recovery after coronary revascularization. The integration with dobutamine echo results seems particularly helpful to further improve myocardial contrast echo specificity and positive predictive values.

Adult↗